1. Field of the Invention
The invention relates to a gliding apparatuses, such as skis. More particularly, the invention relates to gliding apparatuses made of a pair of distinct gliding boards that are each fastened to respective ones of the user's feet.
2. Description of Background and Other Information
Gliding apparatuses of the aforementioned type are generally characterized as skis. Many types of skis are currently used on snow, including alpine skis, cross-country skis, jump skis, short skis, etc. There are also skis adapted for use on water, such as water skis. Skis commonly have an elongated shape extending along a longitudinal axis, and have means for fastening a foot onto the ski. Such fastening means are positioned in a central zone of the ski and ensure that the foot is fastened along the longitudinal axis of the ski. Also common to all skis is their use in gliding in a given direction D, i.e., the gliding axis, which is parallel to or coextensive with the longitudinal axis of the ski. To travel in a straight line, the user keeps each of his skis completely flat while maintaining his weight in the center of the ski. To turn left, the skier shifts his weight to the left side of the ski by pressing down on the left edge; to turn right, the skier shifts his weight to the right edge of the ski. Typically, to make a series of turns, the skier moves successively from one edge to the other by laterally shifting his weight. By using the articulations/joints of the ankles, knees, hips, and spine, the skier can easily modify the position of weight, shifting from front to rear, and vice versa, while keeping his balance. However, the human body is not predisposed to lateral flexing. The ankles, knees, and spine only offer a very small degree of lateral flexion, so that, to shift his weight from left to right, or from right to left, the alpine skier engages his entire body rightward or leftward, respectively. In so doing, the skier becomes laterally unbalanced. As consequence, a pair of ski poles have been necessary to preserve the skier's balance and to enable him to turn more easily at high speed.
In recent years, alpine skis have become shorter. To provide the skier with adequate lift, such skis have become wider at the same time. However, the widening limit for an alpine ski is closely related to the fact that the wider the ski, the more difficult it is to turn it. Indeed, because the skier's foot is positioned, transversely, in the middle of the ski, and because the skier must shift his weight over the inner turning edge, the lever arm, which is substantially equal to half the width, is larger with a wider ski, and the effort required to place the ski on the edge increases. In practice, the use of wide alpine skis is not recommended for small sized users or those who are not physically fit.